To ensure overall voice service reliability and availability, CCS Diagonal (D) signaling link diversity must be established during installations and must also remain physically diverse regardless of the underlying network changes. Due to the many changes and rearrangements that occur almost daily in the optical fiber based transport network, on which these D links traverse, it is a necessity to keep track of where and how the signaling D links are routed in order to maintain the physical diversity. For instance, node A and node Z are interconnected via node W by a transport network using optical fibers. A D link may traverse the A to W to Z route. The network provider decides later that node A to Z will be interconnected directly instead of going through W due to a more efficient routing in the physical layer, such as the optical fiber level. Of course, when the A to Z physical layer routing is changed, the D link that originally rides on the A to W to Z route will also be moved to the A to Z direct route. The network provider must then evaluate if this change will violate the physical diversity requirements by checking if the new D link routing will cause the D link to be routed through the same physical conduits of other D links in the same quad D link group that must be diverse from the first D link. The D Link signaling network diversity is necessary to ensure that connectivity to other Local Exchange Carriers (LECs) or Inter Exchange Carriers (IXCs) have adequate redundancy so that even in multiple link failure conditions, Common Channel Signaling (CCS) System 7, also known as SS7, signaling between voice networks will be uninterrupted. With the introduction of new VoIP related network elements that perform SS7 related signaling functions, the D link diversity issue between a VoIP network and an SS7 network must also be addressed.
Therefore, a need exists for a method and apparatus for network interconnect Common Channel Signaling (CCS) D link diversity monitoring between SS7 and VoIP networks.